Effect

Generations IV and V

Shadow Force causes the user to "vanish instantly" on the turn it is selected, rendering it semi-invulnerable, and then reappear the next turn to cause damage. It will hit the target even if it has used Protect or Detect, and lifts the effects of those moves for the remainder of the turn. Shadow Force will lift the effects of Wide Guard and Quick Guard for the remainder of the turn only if they are used on an opposing team. Shadow Force cannot remove the effects of protecting moves if it does not affect the target (such as if the target is Normal-type).

If Yawn is used the turn before Shadow Force is used, the user will fall asleep and the move will be stopped before it hits (unless Uproar, Insomnia, or Vital Spirit prevents the user from falling asleep). In addition, a foe who has just used Lock-On or Mind Reader can still strike through Shadow Force, as well as if the Ability No Guard is possessed by the foe or the user of Shadow Force.

Wild Pokémon cannot be caught during the semi-invulnerable stage of Shadow Force.

If a Power Herb is held by the user, Shadow Force can be executed in one turn.

Generation VI

Shadow Force will now lift the effects of Quick Guard and Wide Guard when used on allies.

Shadow Force hits a target even if it has used Spiky Shield, King's Shield, or Mat Block, removes that protection for the rest of the turn, and the user of Shadow Force does not suffer the negative effect of that protection move (if any).

In the anime

The middle of Giratina's head crest glows light blue and Giratina's body turns black and disappears as soon as an attack is about to hit it. Seconds later, it reappears behind the opponent and attacks it.

The middle of Giratina's head crest glows light blue and Giratina's body turns black and disappears as soon as an attack is about to hit it. Seconds later, it reappears behind the opponent and attacks it.